In late March 2008, Kilauea Volcano on Hawaii’s big island released a plume of ash and/or steam. The U.S. Air Force Weather Agency reported that the eruption created an area of vog, or volcanic smog, extending westward over the Pacific Ocean.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image of the volcanic emissions on March 24, 2008. Although clouds cover much of the island’s surface, the vog is clearly visible as a plume of dingy gray haze west of the volcano. Vog forms when volcanic pollutants, including sulfur dioxide, mix with oxygen and water in the presence of sunlight.
Kilauea has proven to be Hawaii’s most active volcano during recorded history. It is a shield volcano, meaning it has a low, broad profile that resembles an ancient warrior shield. A series of Kilauean lava flows beginning in 1983 covered more than 100 square kilometers (40 square miles) of the island and destroyed nearly 200 homes.